1. Field of the Invention
The invention relates in general to a temperature compensation circuit, and more particularly to a temperature compensation circuit applied on a metal oxide semiconductor (MOS) transistor for its threshold voltage compensation.
2. Description of the Related Art
In the present age, semiconductor transistor technology has been wildly employed to various kinds of applications. Generally, a transistor, e.g. a metal oxide semiconductor (MOS) transistor, has a threshold voltage. When a bias voltage greater than or equal to the threshold voltage is applied to the MOS transistor, the MOS transistor is turned on with a substantially stable current flowing therethrough; otherwise, the MOS transistor is kept in cutoff state. Conventionally, it is well known that the threshold voltage of a transistor is a function of temperature. In other words, the threshold voltage of the MOS transistor varies with fluctuation of temperature of the MOS transistor. However, there have been demands on transistors with temperature invariant threshold voltage in some applications and how to provide transistors with temperature invariant threshold voltage has therefore become a prominent object for the industries.